<!DOCTYPE html>
<html>

<head lang="en">
  <meta charset="UTF-8">
  <title>jquery each</title>
  <script src="js/jquery-1.11.3.js"></script>
</head>

<body>

  <ul id="list">
    <li>98</li>
    <li>85</li>
    <li>33</li>
    <li>99</li>
    <li>52</li>
  </ul>

  <script>
    //请给每个不足60分的成绩+10分，并将超过90分的成绩用绿色背景标识出来
    $("#list>li").each(function (index) {
      var score = parseInt($(this).html());
      if (score < 60) {
        $(this).html(score + 10);
      }
      if (score >= 90) {
        $(this).css("background-color", "lightGreen")
      }
    });
  </script>
</body>

</html>